A memory device may operate at a low source voltage, e.g., about 0.44V. During read operations of the memory device, a word line driver provides a driving voltage that drives a word line, whereby a bit ‘0’ or ‘1’ of data is stored in a memory cell. However, at such a low operating voltage, a pulse duration of the driving voltage has to be lengthened, e.g., about 28 ns, which is undesirable.